FUNCTION GetResidCrossFlowBothUnmixed(NTU, Par) RESULT (Residuum)
! FUNCTION INFORMATION:
! AUTHOR Michael Wetter
! DATE WRITTEN March 1999
! MODIFIED Fred Buhl November 2000
! RE-ENGINEERED na
! PURPOSE OF THIS FUNCTION:
! From the formula Eps = f(NTU,Z) this function finds the
! residual of f(NTU,Z) - Eps for a cross flow heat exchanger,
! both streams unmixed.
! METHODOLOGY EMPLOYED:
! Uses the effectiveness - NTU heat exchanger formula for cross
! flow, both streams unmixed.
! REFERENCES:
! M. Wetter, Simulation Model Air-to-Air Plate Heat Exchanger
! LBNL Report 42354, 1999.
! Also see:
! ASHRAE HVAC 2 Toolkit, pages 4-3 through 4-5
! USE STATEMENTS:
! na
IMPLICIT NONE ! Enforce explicit typing of all variables in this routine
! SUBROUTINE ARGUMENT DEFINITIONS:
REAL(r64), INTENT(IN) :: NTU ! number of transfer units
REAL(r64), INTENT(IN), DIMENSION(:), OPTIONAL :: Par ! par(1) = Eps, par(2) = Z
REAL(r64) :: Residuum ! residual to be minimized to zero
! FUNCTION PARAMETER DEFINITIONS:
! na
! INTERFACE BLOCK SPECIFICATIONS:
! na
! DERIVED TYPE DEFINITIONS:
! na
! FUNCTION LOCAL VARIABLE DECLARATIONS:
Residuum = 1.0d0- EXP( ( EXP(-NTU**0.78d0 * Par(2)) - 1.0d0) / &
Par(2)*NTU**0.22d0) - Par(1)
RETURN
END FUNCTION GetResidCrossFlowBothUnmixed